#include <REGX52.h>
#include <INTRINS.h>

void Delayxms(unsigned int xms)		//@12.000MHz
{
	unsigned char i, j;

	while(xms--)
	{
		i = 2;
		j = 239;
		do
		{
			while (--j);
		} while (--i);
	}

}

void main()
{
	unsigned char LEDNum = 0;
	P2 = ~(0x01 << LEDNum);
	while(1)
	{
		if(P3_1 == 0)
		{
			Delayxms(20);
			while(P3_1 == 0);
			Delayxms(20);
			
			LEDNum++;
			if(LEDNum >= 8)
				LEDNum = 0;
			P2 = ~(0x01 << LEDNum);
		}
		
		if(P3_0 == 0)
		{
			Delayxms(20);
			while(P3_0 == 0);
			Delayxms(20);
			
			if(LEDNum <= 0)
				LEDNum = 7;
			else
				LEDNum--;
			P2 = ~(0X01 << LEDNum);
		
		}
	}

}